duete; see due, ty 2 ]. syn: duty, obligation refer to something a person feels bound to do. A duty often applies to what a person performs in fulfillment of the permanent dictates of conscience, piety, right, or law: one's duty to tell the truth; a parent's duty to raise children properly.
Mutations in the RB1 gene are responsible for most cases of retinoblastoma. RB1 is a tumor suppressor gene, which means that it normally regulates cell growth and keeps cells from dividing too rapidly or in an uncontrolled way.
Causes of retinal detachment are: 1  Tears or holes in the retina. 2  These may lead to retinal detachment by allowing fluid from the middle of the eye (vitreous gel) to collect under the retina. 3  A common cause of retinal tears is posterior vitreous detachment (PVD).